Demands for touch screen panels are increasing more and more with the fast development of small and portable electronic apparatuses. At present, depending on configuration structures, touch screen panels can be classified into add-on mode touch screen panels, on-cell touch screen panels and in-cell touch screen panels. For add-on mode touch screen panels, the touch screen panel and liquid crystal display (LCD) need to be produced separately and then attached together to form a liquid crystal display with touch function. Add-on mode touch screen panels suffer disadvantages of high manufacturing costs, low light transmission rate and great module thickness. For an in-cell touch screen panel, touch electrodes of the touch screen panel are embedded inside the liquid crystal display which can reduce the entire thickness of the module and further greatly lower manufacturing costs of touch screen panels, hence winning attraction of panel manufacturers.
At present, a capacitive in-cell touch screen panel is realized by directly adding touch driving signal lines and touch sensing signal lines on an existing TFT (thin film field effect transistor) array substrate, that is, two layers of strip-like ITO (indium tin oxide) electrodes that intersect with each other in different planes are manufactured on the surface of the TFT array substrate and act as touch driving signal lines and touch sensing signal lines respectively with inductive capacitors being formed at intersections of two ITO electrodes. The operation process of the touch screen panel is as follows: when touch driving signals are applied to ITO electrodes as touch driving signal lines, voltage signals inducted by the sensing signal lines through the inductive capacitor are detected, and during this period where a human body touches the touch screen panel, the body's electric field acts on the inductive capacitor to cause the capacitance value thereof to change and then change the voltage signals generated by coupling with touch sensing signal lines. It is possible to determine the location of touch depending on variation of voltage signals.
For the above-mentioned structure design of the capacitive in-cell touch screen panel, since touch driving signal lines and touch sensing signal lines are added, it is required to increase a new pattern structure layer for the existing TFT array substrate, which requires adding new processes for manufacturing a TFT array substrate, resulting in increased production costs and adverse effect on improvement of production efficiency.